Discharge base, then plastisol???

[ericheartsu]

Hey Alan, just sent you an email with a ton of trial/error info.

Got it Mike, thanks.  One thing different with this last run is the emulsion.  I was using the 925WR as a matter of fact on past runs and had changed to the CP Tex recently and this was the first run of significant numbers with it so it's probably just not as good of an emulsion as the 925.  I always post-expose so I guess I better bite the bullet and get some hardener in here for the longer runs and also switch back to the 925.  I had zero issues on 500+ shirts with no hardener with the 925 so I'm going back to it.

We use cptex now and have zero problems with it. For longer runs we do use the CCI semi-hardner, and make sure that we tape up our screens really well, using split tape on the squeegee side, and clear tape on the substrate side.

It really depends on the job, but we've had pretty good success using a matsui clear discharge base or matsui white discharge base, through a 110 newman frame.

[Sbrem]

Hey Alan, just sent you an email with a ton of trial/error info.

Got it Mike, thanks.  One thing different with this last run is the emulsion.  I was using the 925WR as a matter of fact on past runs and had changed to the CP Tex recently and this was the first run of significant numbers with it so it's probably just not as good of an emulsion as the 925.  I always post-expose so I guess I better bite the bullet and get some hardener in here for the longer runs and also switch back to the 925.  I had zero issues on 500+ shirts with no hardener with the 925 so I'm going back to it.

925WR just won't die, I bet I've used over 20 years. When something works, it works

Steve

[alan802]

It's possible that I did something wrong on the CP Tex but I went through 3 screens for that job and you should have seen the tape job I did on that SOB, it was epic.  I've still got the last one sitting off to the side so I can examine it so maybe I'll take a pic of that when I can.  I post exposed for a good 10 minutes under the 10K lamp on all 3 screens and it just wasn't enough.  I've got almost an entire gallon of the Tex so I want to go through it but if I still think I'll go back to the 925 when I'm done with it.

[Prosperi-Tees]

For the base you guys are using 80/20 base/white? I just dont understand how that would be brighter than 100% white. Im gonna print a small run this afternoon and am gonna try it.

[tonypep]

Its not brighter, it's softer and easier to overprint. You do not need to discharge the garment to titanium white for an underbase.

[Prosperi-Tees]

For a main white is 100% white the way to go then?

[tonypep]

Yes I usually thin with a bit of water though.

[balloonguy]

I keep saying I want to try a discharge... I have a job (maybe) coming up that sounds just like this. It will be a rainbow (4cp) type print on about 500 each of 4 different shirt colors. I was thinking of a discharge underbase and plastisol on top. I will take any advise I can get.
Do any of the suppliers offer a sample or starter kit. I really want everything I need in one box.
Matt

[alan802]

I keep saying I want to try a discharge... I have a job (maybe) coming up that sounds just like this. It will be a rainbow (4cp) type print on about 500 each of 4 different shirt colors. I was thinking of a discharge underbase and plastisol on top. I will take any advise I can get.
Do any of the suppliers offer a sample or starter kit. I really want everything I need in one box.
Matt

All you need is the emulsion that we've mentioned, the 925 preferably and a good manufacturers "Discharge Base w/ Activator".  You don't need any pigment, or pigmented discharge ink or anything like that, just the straight base.  I like the Jantex Discharge Base FS Sweet, it has served me well but I can't say I've tried any other regular base so others might be better at giving the advice on a better base.  Well, you gotta have a scale too to measure out the correct activator % but those can be found cheap if you don't already have one.  Mix the activator into enough base to get you through the print run and not any more.  Once you add the activator you have to use what you've mixed within 8 hours (I've printed with it 24 hours after mixing without any issue) per the manufacturer's advice. 

[Prosperi-Tees]

I have been using CCI wr25 with great results buy my biggest run so far with this emulsion is 150 pieces so I can't say how well it will do for long runs.

[ZooCity]

Just tossing this out there - I believe over-taping the underside actually accelerates the breakdown of a wb screen. 

I tape minimally on the print side though I do stick a little border around the edge of the emulsion on the backside.  WB ink really likes to wriggle it's way under all your tape it seems. 

I've only done wb using some matsui rc colors on hankys and thin garments and then our TW flatstock inks on paper.  The matsui doesn't even put a dent in a regular Aquasol HV screen (no diazo added), properly exposed, dried and post exposed.  I doubt it could break it down at any length of run.  The TW is more aggressive or, maybe not, since it is used with much thinner stencils and does indeed make an attempt an melting my stencils.  I've found that letting the print side 'breath' helps a lot here.   The underside tends to get slightly damp but if left free of tape will hold for the run. I'm guessing the water evaporates off out the back end or something like that.  In the end, any screen getting damp on the print side has a stencil deficiency and I clearly need to add diazo to those stencils or find an alternate emulsion for those inks but it illustrates my point a little. 

Anyways, this may be completely incorrect or it may be something that's technically true but too difficult to obtain in real life possibly, but it's what I'm seeing in my limited experience.  I feel like you ought to be able to build wb screens that can hold through thousands of prints without over taping the underside or even taping at all. 

Alan you have a 8kw halide unit right?  That little solar entity ought to make wb screens to beat all hell if you expose at full wattage.  Given proper exposure and post exposure, I'd ditch any emulsion that doesn't hold up after being blasted by that thing. 

[Admiral]

I've done a few jobs that came out great with discharge base then plastisols on top.

I used regular packing tape since other tape the water based ink would slip around on.  Worked fine for 600+ pieces.

One thing I had an issue with was that tack on the platens wasn't working due to the dampness.  I was flashing for a couple seconds after the discharge base but tack wasn't quite working, any idea what to do?

[RICK STEFANICK]

use the roll on tack they sell for the  sprayers. works great. the water actually helps it stay tackier..

[Admiral]

use the roll on tack they sell for the  sprayers. works great. the water actually helps it stay tackier..

right now I'm using mostly the Tekmar TP-HV carded on

spray tack for smaller jobs / inbetween to save time

but I'll see if just using the Tekbond TB-HV works better next time